The lengths of a particular animal's pregnancies are approximately normally distributed, with mean u = 268 days and standard deviation o = 12 days. (a) What proportion of pregnancies lasts more than...

The lengths of a particular animal's pregnancies are approximately normally distributed, with mean u = 268 days and standard deviation o = 12 days. (a) What proportion of pregnancies lasts more than 274 days? (b) What proportion of pregnancies lasts between 247 and 277 days? (c) What is the probability that a randomly selected pregnancy lasts no more than 253 days? (d) A "very preterm" baby is one whose gestation period less than 238 days. Are very preterm babies unusual? (a) The proportion of pregnancies that last more than 274 days is (Round to four decimal places as needed.) (b) The proportion of pregnancies that last between 247 and 277 days is. (Round to four decimal places as needed.) (c) The probability that a randomly selected pregnancy lasts no more than 253 days is (Round to four decimal places as needed.) (d) The probability of a "very preterm" baby is. This event (Round to four decimal places as needed.) V unusual because the probability is than 0.05.